Method and apparatus for the practice of oral hygiene using a plurality of pulsated liquid jets

ABSTRACT

A method and apparatus for providing a heterogenous pulsed jet of liquid for stimulating the gum tissue and cleaning the teeth. A nozzle structure in the disclosed system defines a plurality of openings for projecting the liquid in the desired plural paths. The preferred frequencies, pressure limit, area of openings, and a number of embodiments describing alternative shapes for producing the plural paths of pulsed liquid are disclosed.

States Patent [191 Moret et a1. Sept. 4, 1973 [54] METHOD AND APPARATUS FOR THE 3,401,690 9/1968 Martin 128/24 A PRACTICE OF ORAL HYGIENE USING A 133g -k 128/66 tI man 128/66 PLURALITY 0F PULSATED LIQUID JETS 1,995,424 3/1935 Guinness... 128/62 A [75] Inventors: Michel Antoine Cesar Moret; 3,227,158 1/ 1966 Mattingly 128/66 Manfred Bergman; Pierre Jean 3,044,465 7/1962 Anderson et a1. 128/62 A Jousson; Jean Mira, a of Geneva 3,379,192 4/1968 Warren 128/66 Switzerland Wood Institute for Industrial Research & Distribution, Geneva, Switzerland Filed: Mar. 9, 1972 Appl. No.: 233,312

Assignee:

Related US. Application Data Continuation'of ser. No. 887,587,Dec. 23, 1969, Abandoned.

US. Cl. 128/66, 128/62 A [51] Int. Cl A6lll 9/00 [58] Field of Search 128/62 A, 66, 224, 128/230, 24 A [56] References Cited UNITED STATES PATENTS 3,487,828 1/1970 Troy 128/66 3,499,440 3/1970 Gibbs 128/66 FOREIGN PATENTS OR APPLICATIONS 43,057 10/1915 Sweden l28/62 A fir imlzi'y Eikz riiini' lsawrence Trapp Attorney-Ronald P. Kananen ABSTRACT A method and apparatus for providing a heterogenous pulsed jet of liquid for stimulating the gum tissue and Cleaning the teeth. A nozzle structure in the disclosed system defines a plurality of openings for projecting the liquid in the desired plural paths. The preferred frequencies, pressure limit, area of openings, and a number of embodiments describing alternative shapes for producing the plural paths of pulsed liquid are disclosed.

' 2 Claims, ls niawin Figures PATENTEUsEP 41ers SNEHQBFS ENTORS MORET,

INV ESAR RGMAN,

JOV'ISSON VI 4 MW 3 24,14) wns BE JEAN RA MICHEL ANTOINE (C MANFR PIER JEA

0m mm FIG. 6.

FIG; 5.

PATENTEDSEP 4191a SHEEI 3 0F 5 m a m MANFRED BERGMAN,

RRE JEAN JOVISSON 8 E N MIRA NNNNNN 088 g MICHEL ANTOlNE CESAR MORET,

PATENTED 3E? 4 975 SHEET h 0F 5 wk MN INVENTORS MICHEL ANTOINE CESAR MORET, MANFRED BERGMA N QE PIERRE JEAN JOVISSON 8 JEAN MIRA 32 W My ATTORNEYS PATENTEUSEP 41913 3.756; 225 sum 5 or 5 FIG. 10A. FIG. HA.

FIG. I3.

F G. I4.

lavas-rolls MICHEL ANTOINE CESAR MORET, MANFRED BERGMAN, PIERREJEAN JOVISSON 8| JEAN MIRA This is a continuation of application Ser. No. 887,587 filed Dec. 23, 1968, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to a method and apparatus for oral hygiene. More particularly, this invention relates to a method and apparatus for pulsing a jet of liquid for stimulating the gum tissues and cleaning the teeth.

It has long been a problem in the field of oral hygiene to find an effective, safe and efficient solution to the problem of cleaning the teeth and stimulating the gum tissues. One solution to the problem which has been somewhat successful utilizes a pulsed jet of liquid which is directed against the teeth and gums.

One of the aims of the present invention is to provide a process for producing a pulsed liquid jet which is capable of actually producing an optimum massage of the gums, or, more precisely, a reactivation of the capillary circulation in the gums to eliminate venous stagnation without damaging the capillaries or provoking an extravasation or even destruction of the capillaries. Extravasation, as here used, refers to the passage of blood globules through the capillary wall where destruction of the capillary walls results in bleeding due to the rupture of the blood vessels therein.

A second aim of the invention is to produce a liquid jet for cleaning the teeth. While a liquid jet cannot replace tooth cleaning with a tooth brush, a liquid jet causes removal of the remnants sticking to the teeth and in particular, the wastes of nutrition remaining in the interdental spaces after a quick cleaning of the teeth with a tooth brush.

Furthermore, the applicants have discovered that the liquid pressures necessary to obtain even a mediocre cleaning were too powerful on the gums, and sometimes dangerous for the user.

In order to determine the optimum qualities of a liquid jet, and to determine as well the effects produced by various liquid jets on the gums, the applicants have developed a novel research method. The prior art has neglected to note that a simple observation of the gums, particularly of theircolour, contour and morphology, permitted only secondary and indirect conclusions to be obtained concerning the state of the capillary blood circulation, a primordial point for the health of the gums since the external conformation and the physical aspects of the gums can vary for different patients. Thus, the conclusions that can be drawn from such an observation are necessarily superficial and may also vary with the examiner. Thus, these conclusions are generally subjective, rather than objective.

In order to remedy the evident disadvantages of such a clinical evaluation, the applicants have developed a novel procedure for the examination of gums wherein a specially adapted capillary microscope is coupled to a magnetoscope and to a TV system. Therefore, itis possible not only to observe every blood globule in the capillaries, but also, with a luminous flying spot, to measure directly on a television screen the speed of the blood flow in the capillaries.

The speed and the number of glood globules, that is, the average blood volume throughthe capillaries effectively represent the only real and objective criterion sions reached.

which permits the observer to judge the effect of a gum massage treatment in a numerical or empirical way, in dependently of any subjective influence. Such televised recordings of the blood circulation can be reproduced at any time, so that independent observers can also have a-precise idea of the facutal basis for the conclu- This observation process has also been complemented by the examination of the indirect results of the massage. Each week, for a period of three weeks, the gums of a group of patients submitted to a treatment twice a day with liquid jets produced by various processes were examined cytologically. Therefore, the phenomena of keratinization, if any, and their importance were able to be observed. In addition, the effect of cleaning obtained with liquid jets produced by various processes has been determined by calculating the quantity of debris eliminated after a certain time of treatment on patients and on test models. For example, it is possible to deposit a certain and constant amount of debris on test models before the test which provides the basis for making precise measurements. A table of comparative results obtained according to the novel process is attached as Appendix A as a part of this disclosure.

By comparing the results obtained by indirect and external observation of the gums, as described in US. Pat. No. 3,227,158 with the results according to the new above-mentioned methods, the applicants have obtained completely different results which are quite surprising. Those results may be summarized as follows:

a. The maximumrecommendedl internal pressure of the hydraulic circuit of 6.3 l tg/cm which corresponds to 1 to 2 Kg/cm on the gum is much too high. As has been demonstrated by experience, the user of such an apparatus has a tendency to choose the higher liquid pressure because he thinks that the higher liquid pressure has the best and faster effect. Therefore, the user will. experience a feeling of pain in the belief that it is the criterion of a good treatment. In fact, liquid pressures of l to 2 Kg/cm are more than enough to cause dangerous effects on sensitive capillaries, and even to destroy them. b. The recommended pulsation frequency within the range of 800 to 1600 cycles per minute does not produce the optimum effect.

j c. A nozzle with a circular outlet orifice, preferably having a diameter of 0.9 mm, produces a much too thin and homogeneous jet. As a matter of fact, the treated surface, when the nozzle is placed at l or 2 cm from the gums, has an area of about 1 to 3 mm. Therefore, the local pressure effects over that area are not only too high, but it is also practically impossible that all the gum surface could be treated during a minimum length of time, if the user acts with the nozzle as with a tooth. brush, which is generally the case. Furthermore, the horizontal movements of sweeping the gums by the nozzle produce only thin lines of application, of a width of approximately 1 mm that do not overlap or abut, as the user will not generally systematically treat the total gum surface with such a small jet. The liquid flow per unit of time is relatively high, and therefore presents two disadvantages: (1) on one hand, a relatively great quantity of water is a nuisance in the mouth of the user,.and (2) on the other hand, it

prevents an efficient massage and cleaning from being produced. Furthermore, when there is too much liquid, the liquid appears as a continuous water film on the treated surface which breaks the force of the following liquid pulsations.

e. The considerations of the rebounding of gums during the breaks of pulsations are not entirely accurate. Indeed, the gums, which are practically without muscles, form a relatively thin layer above the tooth roots, and contrary to the other tissues, have a very low elasticity. Even if real breaks between two liquid pulsations do not occur, which is generally the case, apulsation frequency of 1,600 cycles per minute, with nearly identical pulsation times and breaks produces a break time of about 18.7 ms. During this short interval, a gum tissue supporting a pressure of several Kg/cm will not rebound fully. Moreover, practical tests have shown that even with a specially made pump, real breaks between two liquid pulsations are not obtainable. In fact, due to'the inertia and to the partial obturation of the liquid by the nozzle which impedes the escape of the liquid jet, the treated surface of the gums still receives a liquid jet during the breaks of the pump so that a reduction of the pressure is achieved, but not to a point of zero pressure between two maximum following pulsations. Tests of the applicants have furthermore demonstrated that, for an efficient massage, rebounds of the gums take practically no part. Moreover, the capillary circulation is activated to the maximum when, after a pulsed pressure produced at a certain frequency which need not be reduced to zero, an adequate disturbance of the laminar jet can be obtained in order to spray the liquid mass on an impact surface sufficiently great that the total kinetic energy of the homogeneous jet is not applied on a practically punctual surface.

A capillary vessel represents a passive pipe, having a diameter which is, in the more favorable conditions, about the size of a blood globule (7-l0u), and the capillary vessel is crossed, very often, by only one globule at a moderate speed.

If a compression effect is produced on the capillary with heterogenous water particles, proportioned for the best conditions in time and space, a purely mechanical pulsation is simultaneously obtained in the capillary that on the one hand, stimulates the circulation, and, on the other hand, creates a bio-chemical activation which liberates histamine-like substances, thus continuing the stimulation of the capillaries.

Thus, the premises upon which the prior art has been developed are not entirely accurate. In sum, heretofore, it was recommended in the art to use a liquid jet emerging from a circular opening, similar to a water jet out from a pipe, to obtain a massage effect on the gums, whereas the tests of the applicants have demonstrated that a homogeneous liquid jet is not recommended.

BRIEF SUMMARY OF THE INVENTION An aim of the present invention is to remedy the disadvantages of known processes for the production of liquid pulsations used for the massage of the gums and the cleaning of the teeth by using jet characteristics that offer a greater security even for unsupervised users and permit a maximum activation of the capillaries of the gums, as well as a good cleaning of the teeth and of the interdental spaces.

The process and apparatus of the invention which remedy the disadvantages of the prior art are characterized as follows:

a. The shape and the division of the nozzle section produces a turbulence at the orifice of the nozzle and creates an heterogenous jet which widens in cross-section, which at a distance of l to 2 cm from the nozzle, sweeps a surface of 15 to 50 mm.

b. The section of the liquid passage at the outlet of the nozzle, which is dimensioned in order to produce, when the jet is at its maximum pressure;

1. a discharge rate of liquid sprayed within the range of 200 to 1,000 ml/min. and preferably between 250 and 500 ml/min.

2. a jet velocity within a range of 10 to 50 m/sec.,

and preferably between 15 and 30 m/secs.

3. a force applied by the jet to the impact surface that does not exceed 36 g.

c. The pulsation frequency on the jet is within the range of 1,000 to 3,600 cycles per minute, preferably above 2,000 cycles per minute.

The total outlet section of the nozzle preferably includes a plurality of individual orifices each having a cross-sectional area of 0.02 to 0.3 mm which, in the case of circular openings, corresponds to a diameter of approximately 0.2 to 0.6 mm. These orifices are distributed on about 3 to 20 mm of the nozzle surface. If this distribution of openings is made on a circular surface,

the diameter of this surface will preferably be about 2 to 5 mm.

Furthermore, it has been proved to be very useful to modulate the liquid jet in function of the maximum amplitude of the pressure, and/or of the frequency.

While the present technical data, and particularly the disclosure of U.S. Pat. No. 3,227,158 established a limit value of the pulsation frequency at about 1,600 cycles per minute, it has been discovered that the optimal frequency, from the point of view of efficiency, must be within a range of 1,000 to 3,600 cycles per minute, preferably above 2,000 cycles per minute.

Furthermore, if a maximum given force of 36 g is used as a preliminary condition, the maximum pressure produced by the liquid jet on the gums must not exceed 0.24 Kg/cm', on an impact surface of 15 mm, while according to U.S. Pat. No. 3,227,158, a maximum pressure of 6.3 Kg/cm was provided in the hydraulic circuit, a value which provides approximately 1.5 Kg/cm' at the impact point on the gums.

It has also been discovered that the necessary heterogenous state and turbulence of the liquid jet are easily obtainable by several orifices, placed near one another on the nozzle, rather than by using only one circular hole which compared to the conventional orifice shapes which produces a very laminar liquid flow.

An even greater heterogenous state and turbulence of the liquid jet are obtained if the holes are not circular, but rather triangular. In principal, an irregular opening used as an outlet orifice is enough to produce a sufficiently heterogenous jet. If the sides of this irregular opening are corrugated or indented, the heterogenous state is enhanced.

In a general manner, it has been demonstrated that the shape, the arrangement and the number of orifices of the nozzle can vary in large limits to produce a sufficiently hereogeneous and turbulent jet which is advantageously different from a laminar homogeneous jet emerging from a circular orifice. Moreover, in such an arrangement, the operating characteristics of the pump producing the liquid jet are not critical, particularly with respect to the variation of the pressure as a function of the time, since, as mentioned above, the pressure never returns to a non-existent value between two liquid pulsations.

An apparatus for the embodiment of the process according to the invention includes a liquid pump operated by a motor and connected to a liquid tank, a valve for the control of the pressure in said pump, and a liquid conduit from the pump and connected to a nozzle. The apparatus is further characterized by:

a. A liquid pump for producing pressure pulsationsat a frequency within a range of about 1,000 to 3,600 cycles per minute.

. A control valve for limiting the maximum pressure of the liquid at the impact point of the jet to a maximum of about 0.24 Kglcm and preferably about 0.1 Kg/cm at a distance of about 1 to 2 cm.

c. A spraying head of an approximately spherical shape, connected to the external extremity of the liquid conduit, wherein the casing includes an accumulation chamber and wherein the internal section has a greater capacity than the supply conduit leading to the spray head which includes a perforated plate serving as a nozzle, and providing an average angle of the liquid jet with respect to the supply conduit.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in a more detailed manner, with respect to the drawings showing various embodiments in which:

FIG. 1 is a schematic view of an apparatus for the embodiment of the process according to the invention;

FIGS. 2-7 are cross-sectional views of several embodiments of spraying heads;

FIGS. 8, 8A, 9, 9A, 10, 10A, 11, 11A, 12, and 13 disclose various orifice configurations for the nozzle of the spraying head; and

FIG. 14 is a split shaped nozzle orifice.

In FIG. 1, the apparatus designated generally at includes a tank or reservoir 21 containing a liquid 22, for example water, connectedto a liquid pump 23 operated by a motor. The pump produces pressure pulsations at a frequency within a range of 1,000 to 3,600 cycles per minute, preferably above 2,000 cycles per minute and is preferably a unit operating according to the principles of the reciprocating piston pump, which is connected to an electric motor having a maximum rotating speed of 3,600 RPM. A pressure control valve 25 is connected to the outlet of the pump 23 and to a liquid conduit 26, at the extremity of which is fixed, and removable, a spray head 28 having a nozzle 29.

As depicted in FIGS. 1 and 3, the spraying head 28 includes a casing in two parts which together form a nearly spherical shape. The rear shell 30 includes a transition portion 31 which defines a liquid conduit 32. The conduit 32 is connected to the supply conduit 26. The rear shell30 also comprises a core 33 which diametrically crosses the inside of the casing. The orientation of the core 33 determines the axis of the jet and is joined to the interior wall thereof. 1

The front shell 34 of the casing defines a bore 39 which nearly corresponds in crosssectional area with the cross-sectional area of core 33 at its forward end. The forward end of core 33 is positioned in the bore 39. The structure of either the bore 39 or the core 33 is such that a plurality of openings 40 are formed therebetween.

The edges of front shell 34 are profiled as designated by reference numeral 35 in order to form a liquid-tight joint designated generally at 36 with the forward edge 37 of the rear shell. The joint 36 may be effected by suitable fastening means, such as press-fitting, welding, or providing the respective parts with mating threads for a threaded engagement.

A plurality of openings 40 are uniformly distributed along the circumference of a circular path defined by the core 33 and the bore 39. Either the bore 39 or the core 33 is shaped to form a liquid-tight seal therebetween at the locations between the openings 40. The diameter of the circle defined by the joinder of core 33 within bore 39 is preferably within the range of 3 to 5 mm, while the diameter of the accumulation chamber 42 defined by the rear shell 30 and the front shell 34 are preferably within the range of 7 to 9 mm. The supply conduit preferably has a diameter of l to 2 mm.

As is shown in the embodiments of FIGS. 3-7, relative dimensions of the front shell 34 and the rear shell 30 may be varied so that the point 36 may be posi tioned either forward, at, or rearward of the midline of the spraying head.

The openings 40 in the shell may have the shapes illustrated in FIGS. 8-11. FIGS. 8, 9, 10 and 11 represent openings which are defined by the structure of the front shell 34 at the bore 39 thereof, which FIGS. 8A, 9A, 10A and 11A show corresponding openings which, in the alternative, may be defined. by the structure of the core 33 at the least at its forward end. The openings thus produced have a length at least equal to the thickness of the front shell 34 at the lever of the bore 33.

As shown, the shape of the openings maybe triangu lar, as designated by numeral 50 in FIGS. 8 and 8A; square as designated by reference numeral 51 in FIGS. 9 and 9A; semi-circular, as designated by numeral 52 in FIGS.'10 and 10A; or split-shaped, as designated by numeral 53 in FIGS. 11 and 11A. The cross-sectional area of these orifices is within the range between 0.02 to 0.3 mm, and preferably within the range between 0.07 0.1 mm.

The number of orifices represented according to the examples of the embodiment is 12, and the total spray section of the nozzle is dimensioned in order that the discharge rate of the liquid is, with a maximum pressure, within the range of 200 to 1,000 ml/min., and preferably within the range of 250 to 500 ml/min., and the velocity of the jet at the outlet of the nozzle is within the range of 10 to 50 m/sec. and preferably within the range of 15 to 30 m/sec.

It has been established that the described shape and arrangement of the nozzle orifices combined with an accumulation chamber in the spraying head produces a liquid jet which is sufficiently heterogenous and um bulent and which widens and sweeps a surface of 15 to 50 mm at a distance of l to 2 cm from the nozzle 29, and also produces a force of 10 to 30 g at the impact area. Due to the jet turbulence in the outlet orifice of the nozzle, there is no proportional relation between the liquid pressure inside the spraying head, the total section of the outlet orifice of the nozzle, and the volume of liquid sprayed per unit time, contrary to the relationships observed for a laminar outflow.

In fact, the greater the perturbation of the laminar flow due to the shape and the arrangement of the orifices, the lesser the liquid-flow sprayed.

This is one of the reasons why theoretical data concerning the pump outlet power and pressure necessary inside the spraying head would not be in and of itself sufficient to define the conditions of an optimum massage effect, since the massage effect is determined only by the characteristics of the liquid jet at the impact on the gums.

These optimum characteristics of the liquid jet have been determined as has been discussed, after systematic research, and can now be reproduced in several ways, for example, empirically, due to the characteritics of the spraying head already described.

In the embodiment illustrated in FIG. 4, the spraying head is composed of a .rear shell 28 which defines a core 33, a front shell 34 defining a bore 39 for receiving the core 33, and a sleeve 60 which forms the central part of the casing 28 and extends the supply conduit 32. The two shells are assembled to form a water-tight seal with the sleeve 60, for example, by suitable fastening means such as' sticking or welding. A plan view passing by the section of sleeve 60 and limited by the interior of the casing is crossed by the core 33.

In the example according to FIG. 5, the rear shell 28 and the core 33 are in one piece and are assembled to the front shell 34 at joint 36. In this embodiment, the front shell and the supply conduit 32 are of a unitary construction.

In the embodiment illustrated in FIG. 6, the core 33 is independent of both the front shell 34 and the rear shell 28, the latter defining the supply conduit 32. The rear portion 62 of the core 33 is connected by insertion into a recess 63 situated in the internal wall of the rear shell 28. With crawling pins 64, the core 33 is rigidly locked with the shell 28, which has corresponding openings in its internal wall. The front shell 34 is screwed to the rear shell 28 to form a point 36. A recess 69 at the front of core 33 enables the unit comprising the shell 34 and the core 33 to be assembled and disassembled. In another possible embodiment not represented here, the rear portion 62 of the core 33 can be screwed into the recess 63 of the rear shell 28. In these conditions, the side of the front shell is rigidly secured by the core 33 against the side of the rear shell.

In each of the embodiments illustrated in FIGS. 4-6, the orifices 40 may have any of the shapes shown in the examples illustrated in FIGS. 8-11.

In the embodiment illustrated in FIG. 7, the casing 28 of the spraying head includes a rear shell 70 fixed rigidly to form a water-tight joint 72. The front shell 71 also defines the supply conduit 32. The front shell 71 defines a bore 73 in which a disc 75 defines a plurality of openings 76 secured by a threaded locking ring 77. The circumference of the ring 77 and the front part of the bore of the front shell 34 have a thread 78. The ring 77, preferably has slots 80 for the use of a suitable screwing tool. The disc 75 with holes has, in the represented embodiment, a diameter of 3.5 mm and possesses 36 openings each having a diameter of 0.20 mm. The disc 75 is illustrated in FIG. 12. Instead of having circular openings, as shown in FIG. 12, disc 75 can as well have radial openings 90. These split-shaped orifices illustrated in FIG. 13 can be formedby the core 33 or the bore 39 according to the principles discussed in connection with the embodiments of FIGS. 2-6.

Finally, a unique oblong split shaped nozzle orifice 95, as illustrated in FIG. 14, is also possible. This split is made in the disc 75, and its side walls are corrugated, or indented, as designated by reference numeral 95,

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

DISCUSSION OF THE CHART DESIGNATED AS APPENDIX A Particularly remarkable effects obtained with the jets produced according to the invention have been re vealed by comparative researches, as shown by the chart designated as Appendix A as follows:

Column I Data from a commercially-used apparatus corresponding to U.S. Pat. No. 3,227,158.

Column II Another commercially-used apparatus.

Columns III-V- Three different apparatuses, ac-

cording to the invention.

Horizontally, the table gives the following details:

Group 1 The number, size, and shape of the nozzle orifices of the apparatus tested. The nozzle orifices mentioned in the apparatus according to the invention in columns IIIV are distributed on a circular surface of approximately 3.5 mm diameter. The 12 triangular orifices of apparatus IV are distributed along the circumference of a circle, as discussed in the embodiment illustrated in-FIG. 8.

Group 2 The basic pulsation frequency of the apparatus in cycles per minute.

Group 3 The pulsation frequencies effectively measured in cycles per minute under a maximum pressure being supported by the user with said apparatus; the liquid flow Q in ml/m ejected from the nozzle, and the force F produced by the liquid jet in grams g acting on the contact surface.

Group 4 The pulsation frequencies in cycles per minute and liquid flow Q in ml/min. measured with a force F applied on the contact surface by a liquid jet fixed at 10 g.

Group 5 The numerical values concerning the massage effect produced.

Group 6 The cleaning effect obtained. The massage effect has been examined and evaluated as follows. The apparatus have been experimentally used on patients during 2 or 5 seconds with various pressures. With the abovedescribed capillary microscope, coupled to a TV screen and to a magnetoscope, the following matters have been observed and measured:

. The speed of blood flux in the capillaries before and after the test; the acceleration of blood flux after the test, as well as its progressive slowing down were measured every 30 seconds during at least five minutes.

b. The number of open capillaries before and after the treatment.

c. The coefficient of blood filling, i.e., the number of erythrocytes passing at a given moment in a capillary.

d. For the evaluation of negative effects, capillaries have been examined in order to determine if there was extravasation, lesion, or even destruction of the capillaries.

e. Furthermore, indirect results of the massage effects have been examined in the following manner: a group of patients were treated twice a day during 21 days. Every 7 days, the gums of the patients were cytologically examined in order to determine whether keratinisation was produced and to what magnitude.

These quantitive and qualitative observations were appreciated by positive or negative points, as it appears in group of the table.

The difference between the positive and negative points has precisely served as a basis for the establishment of a relative factor of efficiency, which has been chosen equal to one in apparatus 1, which represents the lower positive effects. I

The cleaning effects during the treatment have been examined as follows. The number of debris existing on the dental surfaces before and after a certain duration of treatment, on both patients and on test models, permitted the determination of the quantity of debris eliminated during the treatment. Group 6 gives the percentage of wastes taken out during the treatment and from these indications, the approximative relative effect factors have been established. A factor equal to one has again been chosen for apparatus 1.

The efficiencies mentioned in the table for the various apparatuses examined show evidently the superiority of apparatuses III-V according to the invention. From these results, these general conclusions can be drawn:

The results obtained with apparatus 1, as well for massage as for cleaning efficiency are not-sufficient. A reduction of the liquid pulsation frequency at a rate under 700 cycles per minute, as it is the case for apparatus II, with the other conditions remaining identical, increases the massage efficiency with regard to apparatus I, which becomes very small with this low pulsation frequency. Although apparatuses I-II produce practi- I, and respectively three times as great if a cally the same thin and homogeneous liquid jet flowing from a unique circular nozzle orifice of 0.9 mm of diameter, the improved massage effect of apparatus II with regard to apparatus I is explained very likely by the fact that at a pulsation frequency of 700 cycles per minute, the water mass in contact with the gums has more time to escape from the impact point than in the case where the direct effects of liquid pulsations were broken down at the contact point by the continuous presence of a water film, as it is the case for apparatus II. A surprising increase of the massage effect, with regard to apparatus I and to apparatus II, is obtained with the apparatus according to the invention, evidently owing to the following factors: the turbulence and to the division of the liquid jet as in the case of a shower; a gum surface noticeably greater in surface area is treated with a quantity of water which is noticeably smaller, and provokes, because of the higher pulsation frequency, a better capillary reactivation, without neg ative effects as compared to the other apparatuses.

It should be observed that the quantity of water used with the apparatus according to the invention is practically half the quantity of apparatus I and II This means that an eventual absorbtion of the liquid energyby a continuous film is practically avoided, which is not the case when there is heavy water flow.

The impact surface of the liquid jet in the apparatuses III-V according to'the invention is of approximately 25-30 mmflwhile, due to the homogeneity of the jet, the impact surface with a liquid jet according to apparatuses I-II is only 1-4 mm. Consequently, the average pressure produced on the gums by the apparatuses I and II is much more higher, and it creates disadvantages, and this particularly for apparatus I, as the high negative points show. Moreover, the cleaning effects of the apparatus according to the invention columns III-V, are twice as great with regard to apparatus pressure amplitude modulation is performed.

The results given in the table show clearly the superiority of the process and of the apparatus according to the invention for the production of a liquid jet which, in spite of a much superior efficiency, is very simple and can'be industrially manufactured.

Invention I II III IV V 1. Nozzle orifice:

1 1 11 12 11 0. 9 mm. 4: 0.9 mm. 0.3 mm. 0.07 mm." d: 0. 3 mm. Shape. Round Round Round Triangular Round 2. Basic frequency:

uls. min 1. 200 700 3,000 3,000 3,000 1 Pressure modulation nuns/min 300 3. Characteristics under Pm;

l1llS./H1i!. 1,125 590 2, 575 2, 670 2, 590 Modulatioiu. 445 Q, in nlL/min. 450 465 220 215 200 in g 15 15 14 13 14 4. F=10 [,n;

lnisations/min 1, 706 2, 000 2, 590 2, 015 Q in mL/min 375 385 170 160 6. Massage effect:

Positive points. 90 101i 146 148 l-iil N egetivo points... 68 15 14 11 18 Negative-positive. 38 91 131 187 131 Relative efficiency factor... 1 2. 30 3. 45 3. ti 3. 45 6. Cleaning effect:

Eifieieney factor, peroent.... 5-10 5 8 1!) 847 1:124 Relative efficiency factor 1 1 2 2 3 what is claimed is; V

1. A process for the practice of body hygiene by a pulsated heterogeneous jet of liquid, comprising the steps of:

providing a pulsated source of said liquid under pressure to be projected against a selected area on a body,

causing said liquid to flow in a heterogeneous jet comprising a plurality of paths by passing said liquid through a plurality of openings in a nozzle communicating with said liquid under pressure, and

projecting said liquid onto said selected area said method being further characterized in that said jet widens in cross section so that at a distance of about 1 to about 2 cm from said nozzle, said jet sweeps a surface of about 15 to about 50 mm, the section of the liquid passage at the outlet of the nozzle being dimensioned in order to produce, when the jet is at its maximum pressure,

a discharge rate of liquid sprayed within the range of about 200 ml/min. to about 1,000 ml/min., a jet velocity within a range of to 50 m/sec., and

a force applied by the jet to the impact surface which does not exceed about 36 grams.

2. The process as defined in claim 1 wherein the step of providing is further characterized in that the source of liquid is pulsated at a frequency of at least about 2,000 cycles per minute.

3. The process as defined in claim 2 wherein the step of providing is further characterized in that the source of liquid is pulsated at a frequency within the range of about 1,000 to about 3,600 cycles per minute.

4. The method as defined in claim 1 wherein the flow rate of said liquid is within the range of about 250 to about 500 ml/min.

5. The method as defined in claim 1 wherein the velocity of said liquid is within the range of about to 30 m/sec.

6. The method as defined in claim 1 further including the step of amplitude modulating the pressure of said pulsated liquid.

7. The method as defined in claim 1 further including the step of frequency modulating the pulsated liquid.

8. An apparatus for the practice of body hygiene comprising:

means for storing a liquid,

nozzle means defining a plurality of openings for projecting said liquid in a heterogeneous path to a selected area in a body,

said nozzle means comprising a body defining a chamber means for conducting said liquid from said supplying means to said nozzle means, said body further including a wall defining a plurality of openings communicating between the exterior of said body and said chamber means, said openings in said wall each having a cross sectional area in the range of about 0.02 mm to about 0.3 mm, said openings in said wall being distributed over a surface area of about 3 mm to about mm,

means for supplying the liquid under pressure from said storing means to said nozzle means at a pulsation rate of at least about 1,000 cycles per minute, and

means for limiting the maximum pressure of the projected liquid on said selected area to a pressure not greater than about 0.24 Kg/cm.

9. The apparatus as defined in claim 8 wherein said supplying means supply liquid under pressure from said storing means to said nozzle means at a pulsation rate within the range of about 1,000 3,600 cycles per minute.

10. The apparatus as defined in claim 8 wherein said pressure limiting means limits the maximum pressure of the projected liquid on said selected area to a pressure not greater than about 0.1 Kg/cm.

11. The apparatus as defined in claim 8 wherein the cross-sectional area of said chamber in any plane is greater than the cross-sectional area of said supplying means taken along a plane perpendicular to said liquid flow.

12. The apparatus as defined in claim 8 wherein said openings in said wall each have a cross-sectional area within the range of 0.02-0.3 mm.

13. The apparatus as defined in claim 8 wherein said wall has a surface area of about 6-12 mm.

14. The apparatus as defined in claim 8 wherein said body defines a bore, and said wall is a foraminous member disposed in said bore.

15. The apparatus as defined in claim 8 wherein said openings are distributed about the circumference of a circle.

16. The apparatus as defined in claim 8 wherein said body defines a bore and further includes a core member coacting with said bore to define said openings, said core member being connected to the interior wall of said body at a location opposite said bore.

17. The apparatus as defined in claim 16 wherein said core structure defines the shape of said openings.

18. The apparatus as defined in claim 16 wherein said body defines the shape of said openings.

19. The apparatus as defined in claim 16 wherein said body comprises a rear shell including said core, a front shell defining said bore and secured to said rear shell so that a portion of said core is enveloped by a portion of said bore.

20. The apparatus as defined in claim 16 wherein said body comprises a rear shell including said core, a front shell defining said bore, and a sleeve member extending said conducting means, and being connected both said rear shell and said front shell.

21. the apparatus as defined in claim 16 wherein said body comprises a rear shell defining a recess on the interior wall thereof, a front shell defining said bore, and a core member having a portion secured within said recess and another portion secured within said bore, said front shell being secured to said rear shell.

22. The apparatus as defined in claim 16 wherein said body comprises a rear shell defining said conducting means.

23. The apparatus as defined in claim 16 wherein said body comprises a rear shell, and a front shell secured to said rear shell, and a core member secured to said front shell.

24. The apparatus as defined in claim 23 wherein said front shell is threadedly engaged with said rear shell.

25. The apparatus as defined in claim 8 wherein said body defines a bore and said wall is defined by a member disposed in said bore, said member defining a plurality of radially extending slots therein.

26. The apparatus as defined in claim 8 wherein said mozzle means comprises a body which defines a bore and a wall communicating between the interior and the exterior of said body, said wall being defined by a plate disposed in said bore, said plate defining a slot, said slot being defined by at least one irregularly-shaped surface.

27. The apparatus as defined in claim 26 wherein said slot is oblong-shaped and is located approximately along the diameter of said plate and is further defined by a pair of irregularly-shaped walls defining said slot.

ll l i Patent No. 3r756 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Dated Sept. 4, 1973 It is certifi and that Said Lett Col. 2, line and 5, line 3 o line.

Col. 6,

Col. 6, line Col. 7, line Col. 12, line "the should line sh Col. l2,

"mozzle" (SEAL) Attest:

EDWARD M. FLETCHER, JR. Attesting Officer F ORM PO-1050 (10-69) Inventor(s') Michel A. Moret, Manfred Bergman, Pierre Jousson,

& Jean Mira 1 ed that error appears in the above-identified patent ers Patent are hereby corrected as shown below:

page 1, priority should be indicated as follows:

-- Switzerland, No. 16231/69 Filed: October 31, 1969 6, "facutal" should read factual 57, "Sisal and 3" should read FIGS. 2

1, "what" should read What 43 by count (or line 40 by numbering) n read The- 63 by count (or line 58 by numbering) ould read nozzle Signed and sealed this 22nd day of January RENE D. 'IEGTMEYER Acting Commissioner of Patents 

1. A process for the practice of body hygiene by a pulsated heterogeneous jet of liquid, comprising the steps of: providing a pulsated source of said liquid under pressure to be projected against a selected area on a body, causing said liquid to flow in a heterogeneous jet comprising a plurality of paths by passing said liquid through a plurality of openings in a nozzle communicating with said liquid under pressure, and projecting said liquid onto said selected area said method being further characterized in that said jet widens in cross section so that at a distance of about 1 to about 2 cm from said nozzle, said jet sweeps a surface of about 15 to about 50 mm2, the section of the liquid passage at the outlet of the nozzle being dimensioned in order to produce, when the jet is at its maximum pressure, a discharge rate of liquid sprayed within the range of about 200 ml/min. to about 1,000 ml/min., a jet velocity within a range of 10 to 50 m/sec., and a force applied by the jet to the impact surface which does not exceed about 36 grams.
 2. The process as defined in claim 1 wherein the step of providing is further characterized in that the source of liquid is pulsated at a frequency of at least about 2,000 cycles per minute.
 3. The process as defined in claim 2 wherein the step of providing is further characterized in that the source of liquid is pulsated at a frequency within the range of about 1,000 to about 3,600 cycles per minute.
 4. The method as defined in claim 1 wherein the flow rate of said liquid is within the range of about 250 to about 500 ml/min.
 5. The method as defined in claim 1 wherein the velocity of said liquid is within the range of about 15 to 30 m/sec.
 6. The method as defined in claim 1 further including the step of amplitude modulating the pressure of said pulsated liquid.
 7. The method as defined in claim 1 further including the step of frequency modulating the pulsated liquid.
 8. An apparatus for the practice of body hygiene comprising: means for storing a liquid, nozzle means defining a plurality of openings for projecting said liquid in a heterogeneous path to a selected area in a body, said nozzle means comprising a body defining a chamber means for conducting said liquid from said sUpplying means to said nozzle means, said body further including a wall defining a plurality of openings communicating between the exterior of said body and said chamber means, said openings in said wall each having a cross sectional area in the range of about 0.02 mm2 to about 0.3 mm2, said openings in said wall being distributed over a surface area of about 3 mm2 to about 20 mm2, means for supplying the liquid under pressure from said storing means to said nozzle means at a pulsation rate of at least about 1,000 cycles per minute, and means for limiting the maximum pressure of the projected liquid on said selected area to a pressure not greater than about 0.24 Kg/cm2.
 9. The apparatus as defined in claim 8 wherein said supplying means supply liquid under pressure from said storing means to said nozzle means at a pulsation rate within the range of about 1,000 - 3,600 cycles per minute.
 10. The apparatus as defined in claim 8 wherein said pressure limiting means limits the maximum pressure of the projected liquid on said selected area to a pressure not greater than about 0.1 Kg/cm2.
 11. The apparatus as defined in claim 8 wherein the cross-sectional area of said chamber in any plane is greater than the cross-sectional area of said supplying means taken along a plane perpendicular to said liquid flow.
 12. The apparatus as defined in claim 8 wherein said openings in said wall each have a cross-sectional area within the range of 0.02-0.3 mm2.
 13. The apparatus as defined in claim 8 wherein said wall has a surface area of about 6-12 mm2.
 14. The apparatus as defined in claim 8 wherein said body defines a bore, and said wall is a foraminous member disposed in said bore.
 15. The apparatus as defined in claim 8 wherein said openings are distributed about the circumference of a circle.
 16. The apparatus as defined in claim 8 wherein said body defines a bore and further includes a core member coacting with said bore to define said openings, said core member being connected to the interior wall of said body at a location opposite said bore.
 17. The apparatus as defined in claim 16 wherein said core structure defines the shape of said openings.
 18. The apparatus as defined in claim 16 wherein said body defines the shape of said openings.
 19. The apparatus as defined in claim 16 wherein said body comprises a rear shell including said core, a front shell defining said bore and secured to said rear shell so that a portion of said core is enveloped by a portion of said bore.
 20. The apparatus as defined in claim 16 wherein said body comprises a rear shell including said core, a front shell defining said bore, and a sleeve member extending said conducting means, and being connected both said rear shell and said front shell.
 21. the apparatus as defined in claim 16 wherein said body comprises a rear shell defining a recess on the interior wall thereof, a front shell defining said bore, and a core member having a portion secured within said recess and another portion secured within said bore, said front shell being secured to said rear shell.
 22. The apparatus as defined in claim 16 wherein said body comprises a rear shell defining said conducting means.
 23. The apparatus as defined in claim 16 wherein said body comprises a rear shell, and a front shell secured to said rear shell, and a core member secured to said front shell.
 24. The apparatus as defined in claim 23 wherein said front shell is threadedly engaged with said rear shell.
 25. The apparatus as defined in claim 8 wherein said body defines a bore and said wall is defined by a member disposed in said bore, said member defining a plurality of radially extending slots therein.
 26. The apparatus as defined in claim 8 wherein said mozzle means comprises a body which defines a bore and a wall communicating between the interior and the exterior of saId body, said wall being defined by a plate disposed in said bore, said plate defining a slot, said slot being defined by at least one irregularly-shaped surface.
 27. The apparatus as defined in claim 26 wherein said slot is oblong-shaped and is located approximately along the diameter of said plate and is further defined by a pair of irregularly-shaped walls defining said slot. 